example of displayer

Author: Michu1596

examples/displayer.rs

@@ -0,0 +1,84 @@
+use anyhow::Result;
+use futures::StreamExt as _;
+use futures::TryStreamExt as _;
+use scylla::frame::response::result::Row;
+use scylla::transport::session::Session;
+use scylla::DeserializeRow;
+use scylla::QueryRowsResult;
+use scylla::SessionBuilder;
+use tracing_subscriber::field::display;
+use std::env;
+
+#[tokio::main]
+async fn main() -> Result<()> {
+    let uri = env::var("SCYLLA_URI").unwrap_or_else(|_| "127.0.0.1:9042".to_string());
+
+    println!("Connecting to {} ...", uri);
+
+    let session: Session = SessionBuilder::new().known_node(uri).build().await?;
+
+    session.query_unpaged("CREATE KEYSPACE IF NOT EXISTS examples_ks WITH REPLICATION = {'class' : 'NetworkTopologyStrategy', 'replication_factor' : 1}", &[]).await?;
+
+    session
+        .query_unpaged(
+            "CREATE TABLE IF NOT EXISTS examples_ks.basic (a int, b int, c text, primary key (a, b))",
+            &[],
+        )
+        .await?;
+
+    session
+        .query_unpaged(
+            "INSERT INTO examples_ks.basic (a, b, c) VALUES (?, ?, ?)",
+            (3, 4, "def"),
+        )
+        .await?;
+
+    session
+        .query_unpaged(
+            "INSERT INTO examples_ks.basic (a, b, c) VALUES (1, 2, 'abc')",
+            &[],
+        )
+        .await?;
+
+    let prepared = session
+        .prepare("INSERT INTO examples_ks.basic (a, b, c) VALUES (?, 7, ?)")
+        .await?;
+    session
+        .execute_unpaged(&prepared, (42_i32, "I'm prepared!"))
+        .await?;
+    session
+        .execute_unpaged(&prepared, (43_i32, "I'm prepared 2!"))
+        .await?;
+    session
+        .execute_unpaged(&prepared, (44_i32, "I'm prepared 3!"))
+        .await?;
+
+    // Rows can be parsed as tuples
+    let mut iter = session
+        .query_iter("SELECT a, b, c FROM examples_ks.basic", &[])
+        .await?
+        .rows_stream::<(i32, i32, String)>()?;
+    while let Some((a, b, c)) = iter.try_next().await? {
+        println!("a, b, c: {}, {}, {}", a, b, c);
+    }
+
+    // Or as custom structs that derive DeserializeRow
+    #[allow(unused)]
+    #[derive(Debug, DeserializeRow)]
+    struct RowData {
+        a: i32,
+        b: Option<i32>,
+        c: String,
+    }
+
+    let result : QueryRowsResult= session
+        .query_unpaged("SELECT a, b, c FROM examples_ks.basic", &[])
+        .await?
+        .into_rows_result()?;
+   
+    let displayer = result.rows_displayer();
+    println!("DISPLAYER:");
+    println!("{}", displayer);
+
+    Ok(())
+}